#28727: sqlite: CAST to DATE causes error -------------------------------------+------------------------------------- Reporter: direx | Owner: nobody Type: Bug | Status: new Component: Database layer | Version: 1.11 (models, ORM) | Severity: Normal | Resolution: Keywords: | Triage Stage: | Unreviewed Has patch: 0 | Needs documentation: 0 Needs tests: 0 | Patch needs improvement: 0 Easy pickings: 0 | UI/UX: 0 -------------------------------------+-------------------------------------
Old description: > When trying to cast a date object to a `DateField` in `annotate` an > exception is raised: > > {{{ > import datetime > from django.contrib.auth.models import User > from django.db import models > from django.db.models.functions import Cast > > User.objects.all().annotate(today=Cast(datetime.date.today(), > models.DateField())) > > ... > > TypeError: expected string or buffer > }}} > > This only seems to happen with SQLite, MySQL works as expected. > > FYI, this is the SQL which is generated for SQLite: > > {{{ > SELECT "auth_user"."id", "auth_user"."password", > "auth_user"."last_login", "auth_user"."is_superuser", > "auth_user"."username", "auth_user"."first_name", > "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", > "auth_user"."is_active", "auth_user"."date_joined", CAST(2017-10-20 AS > date) AS "today" FROM "auth_user" > }}} New description: When trying to cast a date object to a `DateField` in `annotate` an exception is raised: {{{ import datetime from django.contrib.auth.models import User from django.db import models from django.db.models.functions import Cast User.objects.get_or_create(username="test") User.objects.all().annotate(today=Cast(datetime.date.today(), models.DateField())) Traceback (most recent call last): File "<console>", line 1, in <module> File "/tmp/testenv/lib/python2.7/site- packages/django/db/models/query.py", line 226, in __repr__ data = list(self[:REPR_OUTPUT_SIZE + 1]) File "/tmp/testenv/lib/python2.7/site- packages/django/db/models/query.py", line 250, in __iter__ self._fetch_all() File "/tmp/testenv/lib/python2.7/site- packages/django/db/models/query.py", line 1118, in _fetch_all self._result_cache = list(self._iterable_class(self)) File "/tmp/testenv/lib/python2.7/site- packages/django/db/models/query.py", line 62, in __iter__ for row in compiler.results_iter(results): File "/tmp/testenv/lib/python2.7/site- packages/django/db/models/sql/compiler.py", line 842, in results_iter row = self.apply_converters(row, converters) File "/tmp/testenv/lib/python2.7/site- packages/django/db/models/sql/compiler.py", line 827, in apply_converters value = converter(value, expression, self.connection, self.query.context) File "/tmp/testenv/lib/python2.7/site- packages/django/db/backends/sqlite3/operations.py", line 227, in convert_datefield_value value = parse_date(value) File "/tmp/testenv/lib/python2.7/site- packages/django/utils/dateparse.py", line 61, in parse_date match = date_re.match(value) TypeError: expected string or buffer }}} This only seems to happen with SQLite, MySQL works as expected. FYI, this is the SQL which is generated for SQLite: {{{ SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined", CAST(2017-10-20 AS date) AS "today" FROM "auth_user" }}} -- Comment (by direx): OK, I have updated the original text in the ticket to include the full stracktrace. Replying to [comment:1 Simon Charette]: > Also, I think you'd want to use `annotate(today=Value(datetime.date.today()))` instead. Actually I am doing something entirely different (I need `Coalesce()` and `Max()`) and ran into this issue right there. The above code is just a minimum demonstration on how the bug can be triggered. I know that the code doesn't actually make sense, but I did not want to make the generated query more complex than it has to be for the example. -- Ticket URL: <https://code.djangoproject.com/ticket/28727#comment:2> Django <https://code.djangoproject.com/> The Web framework for perfectionists with deadlines. -- You received this message because you are subscribed to the Google Groups "Django updates" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-updates+unsubscr...@googlegroups.com. To post to this group, send email to django-updates@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/django-updates/063.cfb6ddfd42da1f0999b6ccb2a9d68576%40djangoproject.com. For more options, visit https://groups.google.com/d/optout.